<meta charset="utf-8" />
<p id="time">0</p>
<script>
remindMe(8*60);
function remindMe(seconds){
	if(!seconds){
		var seconds = document.getElementById('time').innerHTML;
	}
	seconds -= 1;
	if(seconds == 0){
		alert('时间到了，快去抢！！！');
		clearTimeout(t);
	}else{
		document.getElementById('time').innerHTML = seconds;
		var t = setTimeout('remindMe()',1000);
	}
}
</script>